Growth of H. salinarum NRC-1 and MPK407 strains for microarray analysis. H. salinarum NRC- 1 and MPK407 strains were grown according to materials and methods as duplicate cultures. Average optical density at 600 nm (OD600) values for the duplicate cultures are plotted for simplicity. The root mean square distance between replicate measurements over the entire growth curve is listed in the figure legend. A table lists root mean square distances (RMSD) between replicates growth curves for sampling points 1-10, 11-20 and 21- the last point. H. salinarum NRC-1 was grown both in the presence and without extra exogenous uracil. The MPK407 strain was only grown in the presence of extra exogenous uracil. Arrows indicate sampling points for totalRNA extraction.